Positioning the dumbbells full forward limits the weight I can use, and I want it to be an upper leg exercise rather than one for delts. It goes without saying that the upper body is not subject to the kind of stress that accompanies a heavy barbell squat. However, why would you think it would not be a mass builder (for upper legs)? You can adjust the weight to do as few or as many reps as you please, and the exercise involves a full range of motion. Yes, there's balance involved, but it gets easier, much like riding a bicycle. I would think that's a good thing for largely the same reason that some people prefer free weights to machines -- working the stabilizer muscles and so on.Quote from atticus:
OK, the way I've seen them done is with a full fwd-raise on the DBs. The movement is less "forward" in contrast to a back-squat which is "ass-out", so you seem to be activating calves a bit as they support when you go past parallel. You're not loading the spine, so it's more of a balance exercise and not something meant to be done heavy. Almost all of lifts are olympic/powerlifting oriented.
I wouldn't think it's a mass builder and it's not something I can do with the ankle.
I've only been doing pistol squats since June, when I revised my routine. I did barbell squats until about 7 or so years ago and concentrated on leg presses since that time, augmenting them with extensions and curls. The weighted pistols are as hard a leg exercise as any I've ever done. So, again, I'm curious to know why you don't view them as potential mass builders.